The proposed studies explore the possibility of a relationship between changes in the cell surface properties of transitional cell carcinomas (TCC) of the urinary bladder and the clinical course of the disease. Detectability of ABH and T antigens, agglutinability by lectins, and sialic acid content of the tumors will be correlated with biological behavior (in particular, frequency of recurrences, invasiveness, and metastases) in an attempt to assess the prognostic significance of such parameters. The mechanism by which cell surface changes are brought about will be studied by following the activities of enzymes involved in the synthesis of ABH substances (glycosyltransferases) and their degradation (glycosidases). Tumor and serum sialyltransferase activities and sialic acid levels will be tested to investigate possible correlations with the course of the disease. It is hoped that these studies will provide important information about the biological behavior of TCC and may give a means of assessing the prognostic outlook of patients with such tumors.